Amazon‘s Price Check app is meant to be used in a brick-and-mortar store. The shopper can say a product name or scan the barcode, take a photo, or do a search for an item with a smartphone, and then the app reveals how much the same item is selling for at Amazon. Last Saturday, though, anyone using the app in a store was given an instant 5% discount off of Amazon’s usual price. Amazon offered a maximum $5 discount off of each qualifying item, and allowed shoppers to get the discount on three items, for a max $15 off.

Soon after Amazon’s promotion made news, many critics weighed in. Gawker used the rubric “EVIL” for its post on Amazon’s Price Check promo, and asked shoppers not to participate in “this cheap, sad thing” (i.e., browsing at a local store before ultimately buying on Amazon with a discount).

Amazon’s promotion — paying consumers to visit small businesses and leave empty-handed — is an attack on Main Street businesses that employ workers in our communities. Small businesses are fighting every day to compete with giant retailers, such as Amazon, and incentivizing consumers to spy on local shops is a bridge too far.

In an op-ed, novelist Richard Russo asked his famous literary friends (all of whom make substantial money from book sales on Amazon) what they thought about the company’s promo. Stephen King called it “invasive and unfair,” and his comments were the least harsh of the bunch. Dennis Lehane called shoppers using the app “Droid-packing” spies, and described Amazon’s actions as “scorched-earth capitalism.”

An Amazon spokeswoman replied (via the New York Times) that the Price Check promotion wasn’t targeting small Main Street businesses at all. Instead, it …

was “primarily intended for customers who are comparing prices in major retail chain stores.” She added that Amazon’s third-party sellers — “more than 2 million individuals and businesses of all sizes that sell on Amazon” — also benefit from the Price Check app.

More obviously, shoppers looking for the absolute cheapest prices benefit from the Price Check app, and they seem to be benefitting at the expense of national chains and local mom-and-pop businesses alike. Based on the early numbers, it appears as if plenty of consumers took Amazon up on its special offer. The smartphone data usage company Onavo says that on Saturday, when Amazon was offering its 5% discount to shoppers using the Price Check app, usage of the app tripled compared to the previous weekend.

Apparently, there are plenty of shoppers who weren’t offended by Amazon’s brazen moves to kill the competition. Or perhaps they were a bit offended, but not enough to refuse a $5 discount.

Brad Tuttle is a reporter at TIME. Find him on Twitter at @bradrtuttle. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.